The document discusses simulation and testing of antennas for 4G LTE-MIMO systems. It describes simulating a PIFA antenna in CST Studio Suite to compare matched and unmatched cases. Results showed improved return loss and far-field patterns when the antenna was matched. Testing of a MIMO antenna system involved measuring isolation between antennas and comparing performance with the enclosure open versus closed.

1. Investigation and Simulation of Antennas for
4G LTE-A MIMO Systems
Presented By:
Vijaykumar Kulkarni
Academic Supervisor: Industrial Supervisor:
Prof. Dr. Ing Heinz Schmiedel Dipl-Ing Mr. Heinrich Fehn

2. 2
PIFA Antenna Simulation
• Importing CAD file
• Setting frequency range & field monitors
• Global & local mesh settings
• Use of AR filter to reduce truncation errors for S-parameters
• Comparison of results for AR filter versus lower energy limit
• Hexahedral & tetrahedral mesh viewing
• F-Solver & T-Solver results comparison
• Adaptive mesh refinement for verification of results
• Antenna matching in CST Design Studio
• Defining new task- S-parameter simulation
• Return loss results comparison for matched and unmatched cases
• AC task settings
• Far field & E field results comparison for matched and unmatched cases

3. 3
Results

4. 4
Flashing, assembling & testing of Audi display
devices- task assigned by Thomas Göggelmann
• Flashing of the new updated version of firmware on
the pcb of display device.
• Assembling of flashed display with the IC and its
mechanical enclosure.
• Testing of the display(testbild); flashing & reflashing
of the display; CAN interfacing and verification of SPI
read/write capability of the device; touchscreen &
external touch interface testing & verification.

5. 5
MIMO concept for Antennas
• MIMO builds on Single-Input Multiple-Output (SIMO), also called receive
diversity, as well as Multiple-Input Single-Output (MISO), also called transmit
diversity.
• So how does MIMO work?
1. MIMO capacity gains come from taking advantage of spatial diversity in the
radio channel
2. Depending on channel conditions and noise levels, the rank (number of
simultaneous streams) can be varied for example the number of streams
can be reduced under poor conditions
3. The performance can be optimized using precoding
• For MIMO to work:
Must have at least as many receivers as transmitted streams
Must have spatial separation at both transmit and receive antennas
More transmitters enables beamforming in addition to MIMO
Best multipath conditions for MIMO optimization

6. 6
 Antenna Diversity: In this technique, we make use of multiple
antennas to receive a signal so that we can combine the replicas of
the received signal in a constructive manner so as to improve the
system performance. As a result we can have better SNR & Gain.
Statistical analysis is used for assesing the performance of spatial
diversity whereas 3D cross correlation function is utilized for the
performance verification of the other two techniques. Different
methodologies employed:
1. Polarization Diversity: Employing of orthogonally polarized antennas.
2. Spatial Diversity: Placing antennas away from each other so that
they can sample signals that are fairly decorrelated.
3. Pattern Diversity: Use of mutiple antennas having different gains in
different directions, which results in variable weighting factors for
the received multipath components.

7. 7
Advantages of MIMO:
• Spatial multiplexing
• Reduction in BER & Enhancement of data rate
• Increment in SNR and SINR
• Minimization of fading effects
• Improvement of channel capacity & spectral efficiency
• Expansion of cell coverage & rise in average cell throughput
• Reliability & lower susceptibility for tapping by unauthorized users
Disadvantages:
• If correlation between antennas is high then channel capacity & diversity gain falls
& multiple stream tx-rx will not be supported
• Two antennas at opposite ends of the same handset (counterpoise) will tend to
excite the same radiating mode and effectively have the same radiation pattern
implying high correlation & low isolation.
• Stringent implications on location and orientation of antennas & it becomes more
crucial in the case of handheld devices.

8. General Antenna design requirements & factors
affecting the real time performance
8
• Isolation (20 dB min. Improved by shaping antennas‘ near field)
• Return loss (10 dB min. Can be achieved by Matched termination &
reduced correlation between adjacent antennas)
• Radiation efficiency
• Multiband support
• Location (min. apart) & orientation of antennas so as to achieve
the required bandwidth
• Controllable directivity for utilizing beam forming
techniques(Improvement of SNR in non MPP environment)
• SINR of 15dB minimum for MIMO
• Antenna ground impedance (should be minimum)
• Selectivity & frequency stability
• Flexible implementation without sacrificing gain
• Cross-polar discrimination
• SAR & HAC compliance(Maximum TX power can be -41.3dBm/MHz)

9. Antenna requirements for the reference antenna
• 4x4 MIMO Antenna system
• 4 antennas for simulation & implementation
• Individual Antenna performance requirements:
• Return loss: Min. 10dB(or 6dB)
• Antenna efficiency: >-3dB in free space
• Multiband support: LTE 700(690-798), GSM 850(824-894), GSM 900(880-960),
GSM 1800(1710-1880), GSM 1900(1850-1990), UMTS/WCDMA 2100(1920-
2170; 2110-2200), LTE 2300(2305-2400), LTE 2500(2500-2690), LTE 3500(),
GNSS(1560-1620), WiFi 5GHz(5150-5850)
• All the 4 antennas must have almost omnidirectional pattern
• Antenna ground impedance (should be min.)
• MIMO Antenna system requirements:
• Isolation: (20 dB min.)
• Envelope correlation coefficient (ECC) between received signals of different
antennas.(It should be less than 0.5 so as to have the advantage of Spatial
Diversity.)
• Controllable directivity for utilizing beam forming techniques(Improvement of
SNR in non MPP environment)
9

10. Antenna requirements for the reference
antenna continued..
• Diversty:
• Spatial Diversity: Location (min. λ/2 apart & orientation of antennas)
• Polarization Diversity: Cross-polar discrimination
• Pattern Diversity: Use of mutiple antennas having different gains in different
directions
• Diversity Gain
• Branch power ratio (k): a measure of power balance between antennas in
MIMO system. It should be between 0 and 3 dB.
• Branch Power imbalance: Mean Effective Gain (Gain balance ratio) (MEG)
(<3dB)
• Cross polarization ratio (XPR)
• MIMO Capacity
10

11. Hindrances
• Lower antenna coupling doesn‘t ensure lower correlation & vice versa.
• Antenna coupling (Currents induced in the common ground plane)
• Direct radiation between different antennas
• Scattering from nearby objects
• Envelope cross-correlation
• It is very difficult to achieve high gain and low correlation across multiple bands.
• Similarly, implementation of antennas with high efficiency that are gain balanced
and independent of each other are also not easy to achieve.
11

12. 12
Monopole Dipole Layered
Antenova
Taoglas

13. Taoglas Antenna: Anechoic chamber passive
measurement setup for 2.4Ghz & 5GHz bands
Copyright e.solutions
1/19/2016
13

14. Taoglas Antenna: 2.4GHz band 3D view
@2440MHz ρ=4m; view at Φ=0°, θ=90° & Ψ=180°
Copyright e.solutions
1/19/2016
14

15. Taoglas Antenna: 2.4GHz band 1D plot
@2440MHz cut taken at Φ=90° over all θ´s
Copyright e.solutions
1/19/2016
15

16. Taoglas Antenna: 2.4GHz band RL, Radiation &
Total Efficiency in dB over all specified frequencies
Copyright e.solutions
1/19/2016
16

17. Taoglas Antenna: 2.4GHz band Maximum Gain
in dBi over all specified frequencies
Copyright e.solutions
1/19/2016
17

18. 18
• Input Power to test Antenna: 16dBm
• Input Signal Frequency: 5.5GHz
• Separation Distance: 50cm
Isolation Characteristics measurement for Monocone
Antenna(test) with reference to Horn
Antenna(reference)

19. 19
Summary of comparison CTS open / closed and Shielding box open / closed
Sheilding box delta open to closed: 24 dB Sheilding box delta open to closed: 30 dB
CTS delta open to closed: 6 dB CTS delta open to closed: 12dB
Facing in front
Facing in front
Facing sideways
Facing sideways

20. 20
Ref -9 dBm Att 20 dB
RBW 500 kHz
VBW 20 Hz
SWT 2.5 s
*
*
1 PK
VIEW
2 PK
VIEW
*
A
3DB
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
1
Marker 1 [T1 ]
-20.54 dBm
5.499983974 GHz
2
Delta 2 [T2 ]
-29.06 dB
0.000000000 Hz1
Delta 1 [T1 ]
0.00 dB
0.000000000 Hz
Date: 15.JUN.2015 13:46:23
Sheilding box delta open to closed: 24dB
Ref -9 dBm Att 20 dB
*
*
1 PK
VIEW
2 PK
MAXH
*
A
3DB
RBW 500 kHz
VBW 20 Hz
SWT 2.5 s
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
1
Marker 1 [T1 ]
-20.54 dBm
5.499983974 GHz
2
Delta 2 [T2 ]
-46.83 dB
0.000000000 Hz1
Delta 1 [T1 ]
0.00 dB
0.000000000 Hz
Date: 15.JUN.2015 14:24:25
Sheilding box delta open to closed: 24dB